1. Field of the Invention
The present invention relates to a process cartridge and an electrophotographic image forming apparatus which can detachably mount the process cartridge.
Here, what is meant by the electrophotographic image forming apparatus is an apparatus to form an image on a recording medium by using an electrophotographic image forming apparatus. The examples of the electrophotographic image forming apparatus include, for example, electrophotographic copiers, electrophotographic printers (for example, laser printers, LED printers and the like), facsimile devices, word processors and multiple devices (multi-function printers and the like).
What is meant by the process cartridge is a process cartridge to integrate charging means, developing means or cleaning means as process means with an electrophotographic photosensitive body into a cartridge and make this cartridge attachable and detachable to and from an image forming apparatus main body or a process cartridge to integrate at least one of charging means, developing means or cleaning means as process means with an electrophotographic photosensitive body into a cartridge and make it attachable and detachable to and from an image forming apparatus main body or an process cartridge to integrate developing means as process means with an electrophotographic photosensitive body into a cartridge and make it attachable and detachable to and from an image forming apparatus main body.
2. Description of Related Art
Heretofore in the past, the electrophotographic image forming apparatus using an electrophotographic image forming process has adopted a process cartridge system, which integrates the electrophotographic photosensitive body and process means for operating on the electrophotographic sensitive body into a cartridge and allows for attachment and detachment of the process cartridge to and from the image forming apparatus main body. According to this process cartridge system, maintenance of the device can be performed not by the serviceman but by the user himself and, therefore, it is possible to enhance the operability remarkably. Hence, this process cartridge system has been widely used in the image forming apparatus.
In order to obtain a good (fine) image in the electrophotographic image forming apparatus using such a process cartridge, it is necessary that the process cartridge is mounted accurately at a predetermined position inside the electrophotographic image forming apparatus main body and interface portions of various electrical contacts and driving transmission parts are accurately connected.
In FIG. 24 is shown a process cartridge PC, and FIG. 25 shows a guide groove GL provided in the image forming apparatus main body PR. In FIG. 26 is shown the image forming apparatus adopting such a process cartridge PC.
With respect to attachment and detachment of the process cartridge PC to and from the image forming apparatus main body PR, as shown in FIGS. 24 to 26, a positioning boss CB is provided on a shaft line of the photosensitive body drum which is the electrophotographic photosensitive body of the process cartridge PC and a guide groove GL which guides the positioning boss CB and positions it is provided on the image forming apparatus main body PR. When the user inserts the process cartridge PC up to a predetermined position along a mounting guide GL as a cartridge mounting guide, a butting portion P provided in the image forming apparatus main body PR abuts against the process cartridge PC and is whirl-stopped with the positioning boss CB as a center. The product having such a constitution has been put to practical use.
As shown in FIG. 26, the process cartridge PC is attached with a drum shutter DS, which covers the surface of the photosensitive body drum when taken out of the image forming apparatus main body PR and exposes the surface of the photosensitive body drum when mounted on the image forming apparatus main body PR. Opening and closing of the drum shutter DS is performed by linking with the inserting operation and pulling operation performed by the user of the process cartridge PC for the image forming apparatus main body PR.
Further, there have been conceived and put to practical use those cartridges, which are provided with a spring to energize the opening/closing cover C of the image forming apparatus main body PR to a mounting direction.
Or as shown in FIG. 26, there have been available also those cartridges in which a back cover UC which imitates the outer shape of the process cartridge PC is fixed to the inside of the opening/closing cover C and, by closing the opening/closing cover C, the process cartridge PC is pushed into a normal position.